Spindle mounting

ABSTRACT

Disclosed is a spindle mounting means carried in part by the spindle rail in the form of a convex spherical seat surface at the spindle receiving orifice and more than two joining holes thereabout which are threaded, and in part by the spindle assembly in the form of an encircling mounting member rigidly fixed thereto having a complementary convex seat surface for abutment with the rail seat and a laterally extending flange extending outwardly from the seat, the flange having a similar number and spacing of joining holes which are not threaded but are of larger diameter than the joining holes of the rail, and a similar number of joining and fixing members in the form of bolts which are passed through the wider flange holes and threaded and tightened into the rail holes, whereby spindle plumbing using this construction is achievable within five to fifteen seconds versus five to fifteen minutes with prior art constructions.

United States Patent 1 Anderson et a1.

SPINDLE MOUNTING Inventors: Gordon C. Anderson, Clemson;

Frank E. Brooks, Seneca, both of S.C.

Saco-Lowell Corporation, Easley, S.C.

Filed: Oct. 9, 1973 App]. No.: 404,833

Assignee:

US. Cl. 57/130, 57/132 Int. Cl. D0lh 7/10, D0lh 7/08 Field of Search 57/112, 122, 129, 130,

References Cited UNITED STATES PATENTS 12/1863 Fethney 57/136 X 5/1885 Thomas 7/1942 Cotchett..... 8/1946 Kennedy. 1/1968 Stiepel et a1. 57/130 X Sept. 17, 1974 Primary ExaminerDonald E. Watkins Attorney, Agent, or Firm-Donald H. Feldman [57] ABSTRACT Disclosed is a spindle mounting means carried in part by the spindle rail in the form of a convex spherical seat surface at the spindle receiving orifice and more than two joining holes thereabout which are threaded, and in part by the spindle assembly in the form of an encircling mounting member rigidly fixed thereto having a complementary convex seat surface for abutment with therail seat and a laterally extending flange extending outwardly from the seat, the flange having a similar number and spacing of joining holes which are not threaded but are of larger diameter than the joining holes of the rail, and a similar number of joining and fixing members in the form of bolts which are passed through the wider flange holes and threaded and tightened into the rail holes, whereby spindle plumbing using this construction is achievable within five to fifteen seconds versus five to fifteen minutes with prior art constructions.

11 Claims, 1 Drawing Figure SPINDLE MOUNTING BACKGROUND OF THE INVENTION This invention relates to spindle mounting means carried in part by a spindle assembly and in part by a spindle rail of a textile yarn processing machine for the accurate and rapid plumbing of the spindle blade vertical and axially central to a vertically traversible spinning or twister ring such that the latter is concentric thereto.

In the erection of textile yarn processing machines employing generally vertically disposed spindle assemblies rotatable to receive yarn wound thereabout by concentric, vertically traversible ring assemblies employng travelers, the vertical support members are usually plumbed to be precisely vertical, and longitudinal and lateral cross-members are usually leveled to be horizontal. One such fixed cross-member extending longitudinal the machine is the spindle rail and another longitudinal cross-member, which however is supported for vertical movement, is the ring rail, each rail being substantially horizontally parallel the other and bearing at spaced intervals therealong corresponding axially concentric orifices about vertical axes at said intervals to respectively receive therein spindle assemblies and ring and traveler assemblies for mounting such that each ring upon vertical traverse is concentric the vertical axis of the spindle blade of its assembly. In order to achieve the required concentricity, not only are the ring rail, and, if used, the lappet-type ring holders leveled to be horizontal during vertical reciprocatory traverse, but it is necessary to plumb each corresponding spindle assembly such that its spindle blade is generally vertical and precisely axially central the corresponding ring along the range of the latters vertical traverse. For these purposes, many devices and methods have been disclosed and/or usedin the prior art in recognition of the correlation between accurate spindle plumbing and the formation of stable packages of yarn (wherein there shall be no sloughing off of end wrapped layers of yarn during its unwinding from the package or in package handling, which are required in subsequent processing, as may otherwise be caused by inaccurate winding of yarn wraps due to nonconcentric ring traversings wherein overlaying yarn wraps can shift relative underlaying yarn wraps).

Within more recent times, the need for accurate vertical plumbing of spindles was made evident from the point of reducing spindle vibrations upon rotation at high speeds in order to assure the prolonged useful lifetimes of spindle assembly components such as bearings; this was considered, for example, by Higgs, in his article Vibration Behavior of the Textile Spindle, paper number 63-TEX-l as published by the American Society of Mechanical Engineers on Mar. 27, 1963.

Still more recently, the need to reduce noise generating vibrations has become recognized in assuage of the health hazards which may be present to operators of textile yarn processing machines, which assuage includes the desirable reduction of vibrations produced as a consequence of non-concentric traversing of rings about spindles and of the precession-type rotational characteristics of inaccurately plumbed spindle blades and yarn packages thereon.

In the prior art, to the advent of this invention, the attempts advanced to plumb spindle assemblies vertical and axially central to their corresponding ring assemblies involved for each such spindle assembly tedious efforts on the part of the operator which consumed prodigious amounts of time, often and commonly being from 5 to 15 minutes. When one considers that a typical textile yarn processing mill may have, for example 10 twisters with a hundred spindle assemblies each and twenty spinning frames with three hundred spindle assemblies each, totalling some 7,000 spindle assemblies which must be plumbed as aforesaid, and each plumbing thereof consuming an average of 10 minutes according to the prior art, the time involved for this single operation would amount to some 1,167 man-hours or almost one-half man-year. Thus, not only does this involve a considerable labor expense, but equally if not more important the spindles concerned are unproductive for considerable periods of time. Beyond this, the tedium involved in spindle plumbing of even one assembly is pronounced and better understood when one considers that an operator must assume a crouching and/or bending position for the prior art intervals of from five to fifteen minutes while making tilting adjustments to the spindle assembly. Thus, for such a tedious job, not only is it difficult to obtain or retain the trained labor needed, but diligent labor fatiguing after the plumbing of several spindle assemblies may be less diligent in accurate plumbing of subsequent assemblies, leading to all manner of difficulties in yarn processing at these latter assemblies; yet further, due to the te dious nature of the effort, labor requires rest intervals between the plumbing of one assembly and the next, thus substantially extending the aforesaid time intervals when the spindles are out of production to about twice the time which is required in the plumbing effort, and which increases the labor costs for plumbing of assemblies in the aforesaid typical mill to that for about 1 full man-year.

In the prior art, to the advent of this invention, in order to effectively plumb spindle assemblies axially central their corresponding rings, machine manufacturers made special and costly efforts to produce spindle rails with a very high degree of planarity; the difficulty and high costs involved in this endeavor may better be understood when one considers that a typical length of such a rail may extend to nine or ten feet per section, and such lengths may have to endure an extra planing operation to achieve the needed planarity of the spindle assembly supporting surface. Beyond this, in the erection of the rail sections onto the machine, much effort was expended to effect the necessary adjustments of each section to achieve coplanarity with all of the other sections and also to achieve a precisely horizontal disposition of the spindle supporting surface of the entire rail, adding much cost.

L. M. Cotchett, in his U.S. Pat. No. 2,289,903 entitled Spindle Mounting, disclosed a spindle assembly mounting means which bears some superficial similarities to that of the present invention. Therein is disclosed the use of spherically surfaced seating members used for tilting adjustment of the spindle blade about a spherical center residing on the rotational axis of the blade at the elevation of the lowest yarn wrap to be wound by the spindle and ring and traveler assemblies. The aforesaid members included an upper one bearing a lower concave seat surface which member was keyed to the spindle assembly in encircling arrangement thereto to prevent relative rotation therebetween, and a lower one loosely encircling the lower portion of the spindle assembly and positionable on the spindle rail for clamping thereto, the lower member bearing an upper convex seat surface for abutment with the concave seat and adjustable movement of the latter for tilting the spindle assembly in a plumbing operation. Use of the Cotchett construction for plumbing requires about 5 minutes per assembly, because of the tendency for slippage shifting of the components during tightening of the bottom lock nut beneath the spindle rail, which nut effects the abutment fixing into position of all of the otherwise loosely encircling components, and for the need to reach beneath the spindle rail for tightening the lock nut and also the holding of the spindle blade in a plumbed orientation above the spindle rail to effect such abutment fixing. However, to the advent of this invention, the foregoing construction known as the New Era Spindle in the art afforded significant reductions in time required to plumb spindle blades over that previously known' Despite the foregoing, the New Era spindle construction was rarely used for the heavier constructions required of twister spindles because of the lock nut type of adjustments which it required and the slippage problems on tightening; further, in twister applications, wherein such machines employ the lappet type of ring holder'which itself is adjustable, the need for such a type of expensive and many-component spindle assembly mount was minimal.

Yet another spindle assembly mounting means of the prior art, usable with twister machines using the lappet type ring holder, which bears some superficial similarity to that of the present invention, was commercially introduced to the art in 1969. It is described in the Stiepel et al US. Pat. 3,364,670 entitled Spindle Control Mechanism at column 2, lines 50 to 58, and in the June, 1969 publication Instruction Manual (First Edition) Tube Drive Twister by Saco-Lowell at pages 20 through 22 in the section entitled Spindles; the latter describes the plumbing operation and more particulars of construction as follows:

The spindle is attached to the spindle rail by a locking ring, held in place by three cap screws. The convex surface of the spindle mount fits into the concave top of the locking ring. Insert the assembled spindle and ring upward through the hole in the spindle rail. Place the cap screws through the holes provided in the spindle rail and thread them into the locking ring beneath the rail. Run them all the way in, but do not tighten.

Place the plumbing gauge on the spindle, as shown in FIG. 13, and tighten the cap screws with the wrench Tightening one screw more than the other will tilt the spindle. Tighten the screws progressively, meanwhile watching the circular level of the plumbing gauge to keep the spindle exactly vertical. Tighten the three screws securely.

Constructions of the prior art require a horizontally disposed spindle rail which has an upper surface with a high degree of planarity and is horizontally level; they have mounting means having components which can positionally shift during the plumbing operation and locking into position; often they require that adjustments and locking be effected from beneath the spindle rail, while holding components above the spindle rail such as the blade in the desired plumbed position and concomittantly watching the bubble level to acertain any deviations during adjustment and locking from such plumbed position; all of the foregoing resulting in the need to expend from 5 to minutes in plumbing of each spindle assembly with use of the highly planar and horizontal spindle rail.

Thus, it is to the assuage of the foregoing disadvantages, problems and difficulties that the present invention is directed, such being a primary object thereof.

Another object of the invention is to provide spindle mounting means for the rapid and simple plumbing of its associated spindle assembly axially central to its associated ring in the range of vertical reciprocatory traverse of the latter, despite an imprecise planarity andfor tilting from the horizontal of its associated spindle rail.

Further desirable objects and advantages of the invention shall become evident from and/or are inherent in the explanations and descriptions which follow.

SUMMARY OF THE INVENTlON It has now been discovered that the objects and advantages of the invention are attained by the elimination of otherwise loosely conjoined components of a mounting means intermediate the spindle rail and the spindle assembly, and by the direct joining of the spindle assembly and the spindle rail in an adjustable mannet for the tilting of the spindle assembly into a plumbed orientation such that the ring is axially concentric to the rotational axis of the spindle blade throughout the range of the formers vertical traverse The present construction, while employing concave and convex spherical seats similar to those in the prior art, has its concave seat carried by the spindle rail in a pre-fixed condition relative thereto which requires no adjustment and its convex seat is rigidly fixed to the spindle assembly. The direct joining of spindle assembly and rail are effected by screw bolts, nuts and bolts or cap screws between a flange, extending laterally outwardly from the convex seat of the spindle assembly, and the spindle rail itself. Using this much simpler construction, plumbing of a spindle assembly consumes but five to fifteen seconds, and tilting and locking adjustments may be made entirely from above the spindle rail reducing the tedium otherwise involved and errors which otherwise may occur thereby. The present mounting means further provides the advantage of being employable, in various embodiments, with either top or bottom entry spindle assemblies with equal efficacy, whereas prior art constructions required usage only with one type of entry spindle assembly. Beyond these, the present construction may, as shall be explained, be employed with spindle rails which are not precisely horizontal and with an imperfect degree of planarity of their top surface.

Adjustability of the spindle assembly, according to the invention, to the axially central position of the spindle blade relative its associated ring through the latters range of traverse, is simply, rapidly and easily achieved with the present construction. The bolt holes in the spindle assembly flange and those in the spindle rail, while of similar plurality (more than two) and spacing are of different diameters; the holes in one closely confine the joining bolts so that there is no play between that one and the bolts while the holes in the other are of larger diameter so that one may, before tightening fully the bolts, tilt the assembly to the desired plumbed orientation about the spherical center of the aforesaid seats despite any imperfection in horizontal orientation or planarity of the spindle rail and by tightening the bolts sequentially and fully fix the spindle assembly at such orientation.

DRAWING A better understanding of the invention may be had from the descriptions and explanations of a preferred embodiment thereof when taken in conjunction with the appended DRAWING, in which;

The FIGURE, in front elevation partially fragmented, shows the present spindle mounting means employed with a top entry, bottom drive spindle assembly mounted on a non-horizontal spindle rail.

EMBODIMENT With reference to the FIGURE, a typical top entry, bottom drive twister spindle assembly, generally designated 10, is shown mounted on a spindle rail 12 of a twister machine (not otherwise shown), by mounting means of the invention, rail 12 being tilted somewhat from a precisely horizontal orientation as may occur through adjustment errors in its erection or by uneven settling of the floor beneath the machine. Assembly is designated top entry because it is passed through the receiving orifice 14 of rail 12 from above the rail, and bottom drive because its whirl 16 is below rail 12, and at the bottom of assembly 10. The spindle blade 18 of assembly 10 is shown as plumbed axially central to its associated vertically traversible ring 20 in the range of such traverse from elevation designated A to elevation B, despite non-horizontal disposition of rail 12, by the present mounting means. Elevation A is the elevation of the lowest wrap of yarn to be wound by assembly 10 and ring 20.

Rigidly fixed to assembly 10 is a mounting member, generally designated 22, of the invention having a spherical surface 24 seat which is convex having its spherical center on the axis of rotation of blade 18 at elevation A; extending laterally outwardly from surface 24 is a flange 26 formed with a plurality of holes 28, 30, 32 therethrough spaced from one another about surface seat 24, hole 32 being behind assembly 10 as shown. In similar manner, rail 12 in the portion around orifice 14 has a spherical concave surface seat of complementary arcuity to convex surface 24 of member 22 for abutment therewith asshown, and its spherical center being coincident with that for surface 24; further, said portion of rail 12 also has formed therethrough a similar plurality of holes 36, 38 and 40 of similar spacing therebetween as holes 28, 30 and 32 about seat surface 34; however, it is to be noted that the cross sectional diameter of flange holes 28, 30 and 32 is larger than that of rail holes 36, 38 and 40, and also the walls defining the latter set of holes are threaded. Joining the spindle assembly 10 directly to rail 12 is effected by a similar plurality of bolts 42, 44 and 46 respectively having bolt heads 48, 50 and 52 and threaded portions 54,

56 and 58 passing through holes 28, 30 and 32 and being threaded into rail holes 36, 38 and 40.

OPERATION OF THE INVENTION In order to plumb spindle blade 18 axially central to ring 20 throughout the latters range of traverse from elevation A to elevation'B, assembly 10 is passed into rail orifice 14 from the top of rail 12 such that convex seat surface 24 abuts concave seat surface 34. Assembly 10 is then rotated until respectively spaced flange holes 28, 30 and 32 are aligned with their counterpart holes 36, 38 and 40 in rail 12, and bolts 42, 44 and 46 are inserted through the flange holes and are threaded into the rail holes. Using a common bubble-type level fixture which is insertable onto blade 18, assembly 10 is tilted to a substantially vertical orientation by rotating it about the aforesaid spherical center of surfaces 24 and 34, whereupon bolts 42, 44 and 46 are successively tightened to secure assembly 10 to rail 12 in the plumbed orientation. In such successive tightening, the bolts are first threaded into holes as first mentioned until there is no manual play of the assembly, and then while watching the level bubble, as appropriate one and another of the bolts are further tightened until an exact centering of the bubble is achieved. In this process, it is assumed that ring 20 is held in a lappet type ring holder secured to a ring rail or bar, such holder having previously been leveled to an exact horizontal disposition. However, there are instances wherein the axis of the ring generated as a line in the range of its vertical traverse is not precisely vertical but may be at an angle, a small angle to true vertical. In those instances, one may employ another type of gauge which fits onto the ring with a central hole therethrough just slightly larger than the diameter of blade 18. Ring 20 hearing this gauge is set atthe lowest elevation of the formers traverse at elevation A and then at elevation B. At elevation B, the gauge holds the top of blade 18 such that its axis of rotation is exactly coincident with the axial line generated by traversal of ring 20; thereupon the bolts are tightened as aforesaid, fixing assembly 10 in-the desired orientation.

CONSTRUCTIONAL VARIATIONS The present invention contemplates yet other embodiments form that shown and described to achieve the present objects and advantages. For example, using a bottom entry spindle assembly driven either from below or above the spindle rail, the mounting member would be positioned with its convex surface facing upward to abut a concave spherical surface carried by the spindle rail at its under surface. Therein, the bolt holes in the rail may be threaded and of smaller cross sectional diameter than those corresponding ones in the flange of the mounting member and threaded, with the bolt heads abutting the under flange surface and the ends of the threaded portions having slots for bolt tightening using a screw driver from above the spindle rail. Altemately, when permissible, the bolts may be tightened from below the rail by a wrench. Using a similar bolt orientation with slotted ends, with a top entry spindle assembly otherwise as shown in the FIGURE, the holes in the flange may be threaded and those of the rail may be of larger diameter and tightening may be achieved with a screw driver as described. Thus, by appropriate arrangement of threaded holes and wider holes and threaded bolts one may employ the present mounting means with top or bottom entry and/or drive assemblies. Other embodiments may employ nonthreaded holes, in both the flange and rail one set of which having cross sectional diameters greater than the other, and the other having diameters just sufficient to receive therethrough joining members such as bolts with threaded ends to receive lock nuts.

From the foregoing, it is now easily understood that the adjustability of the spindle assembly to the desired hereinbefore defined plumbed position, despite nonhorizontal and/or non-planar condition of the rail and despite a non-vertical disposition of the center line generated by the rings center during its traverse, is made possible in the present invention by the combination of the aforesaid spherical surfaced seats carried by the rail and the mounting member, the direct joining of rail and mounting member in a manner permitting movement of the latter about the spherical center of their respective spherical surfaces, and in particular in the preferred embodiments the difference in cross sectional diameters of the joining holes which permit such movement, and the direct fixing of rail and the mounting member at the desired orientation, such as by the bolts tightening as described. Most generally, since the mounting member is always rigidly fixed to the spindle assembly, it may be considered to be a part of the spindle assembly housing which is to say a non-rotatable member of the spindle assembly. While in the most preferred embodiments, the spherical center about which the spindle assmblyis located on the axis of of spindle blade rotation at the elevation of that at which the lowest wrap of yarn is to be wound by the spindle assembly, which is to say that it is at the lowest elevation of the ring in its range of traverse, because such location of the center makes it most simple to plumb the assembly, such center alternately may reside on the rotational axis at any elevation within such range and preferably in the range of the lower half of the spindle blade for in the latter instances plumbing is attainable.

Regarding the convex seat surface hereinbefore described as carried by the spindle rail and shown in the FIGURE as being integral with the rail, alternatively the surface may be on an insert placed into the spindle receiving orifice of the rail and secured to the rail thus also to be considered to be carried by the rail.

Having described in detail the nature of the invention and a preferred embodiment thereof and explained the principle thereof, one skilled in the art may immediately think of yet other variations of construction beyond those here explained which achieve the objects and advantages of the invention and fall within the purview of its definitions as now claimed.

That which is claimed is:

1. In a textile yarn processing machine having a substantially horizontal spindle rail fixed longitudinally thereto; a vertically reciprocable, substantially horizontal ring rail interconnected with said machine for said vertical reciprocatory traverse relative thereto and extending substantially parallel and above said spindle rail; a spindle assembly joined to said spindle rail having a vertically disposed spindle blade with a similarly oriented .axis of rotation; and a ring and ring traveler assembly joined to said ring rail for traverse therewith disposed in a substantially horizontal orientation encircling said spindle blade in the range of said traverse; the improvement comprising:

spindle assembly mounting means for directly mounting said spindle assembly upon said spindle rail such that said blade is oriented axially central to said ring assembly throughout said range of vertical traverse; said mounting means comprising:

a mounting member fixed to said spindle assembly, bearing a spherical convex surface encircling said assembly and extending outwardly thereof, and a mounting flange extending laterally outward from said surface;

a spherical concave surface carried by said spindle rail, of complementary arcuity to said convex surface of said mounting member for adjustable abutment therewith and defining a receiving orifice through said spindle rail for said spindle assembly; and joining means a. for directly joining said mounting member flange to said spindle rail,

b. for adjustably tilting said spindle blade and assembly to an orientation wherein said ring assembly throughout the range of said traverse is axially concentric to said rotational axis of said spindle blade, and

c. for directly fixing said spindle assembly rigidly to said spindle rail at said orientation.

2. The improvement as in claim 1, wherein said convex spherical surface of said mounting member has its spherical center on said axis of rotation of said blade.

3. The improvement as in claim 2, wherein said spherical center of said convex surface is on said axis of rotation in the range of the lower half of said blade.

4. The improvement as in claim 3, wherein said spherical center on said axis of rotation is at an elevation corresponding to the elevation of the lowest wrap of yarn to be wound by said spindle assembly.

5. The improvement as in claim 1, wherein said concave spherical surface carried by said spindle rail has its spherical center on said axis of rotation of said blade.

6. The improvement as in claim I, wherein said joining means is carried in part by said flange and in part by said spindle rail.

7. The improvement as in claim 6, wherein said joining means includes a portion of said spindle rail circumferential said concave spherical surface carried thereby, formed with a plurality in excess of two holes therethrough, said holes forming a set thereof and being spaced from one another about said concave surface,

a portion of said flange of said mounting member circumferential said convex spherical surface thereof, formed with a similar plurality of other holes therethrough forming another set of holes and being similarly spaced from one another about said convex surface as are said holes through said spindle rail, and

a similar plurality of adjustable joining and fixing members engageable with corresponding parts of said portions of said spindle rail and said mounting member flange through the corresponding holes of said sets thereof.

8. The improvement as in claim 7, wherein the walls defining the holes of one of said sets have a greater diameter cross section than that of the second set, and the walls of said second set are threaded.

9. The improvement as in claim 8, wherein said adjustable joining and fixing members are threaded bolts, the bolt heads of which are engageable with one of said portions of said spindle rail and flange and the threaded portions of which are engageable with the threaded walls of said second set of holes, wherein said portion so engageable and said threaded walls are in different ones of said portions of said spindle rail and said flange.

10. The improvement as in claim 9, wherein said threaded walls are in said spindle rail portion and said concave and convex surfaces in abutment with one another are above the lower horizontal surface of said spindle rail portion.

1 1. The improvement as in claim 1, wherein said convex surface is integral with said spindle rail. 

1. In a textile yarn processing machine having a substantially horizontal spindle rail fixed longitudinally thereto; a vertically reciprocable, substantially horizontal ring rail interconnected with said machine for said vertical reciprocatory traverse relative thereto and extending substantially parallel and above said spindle rail; a spindle assembly joined to said spindle rail having a vertically disposed spindle blade with a similarly oriented axis of rotation; and a ring and ring traveler assembly joined to said ring rail for traverse therewith disposed in a substantially horizontal orientation encircling said spindle blade in the range of said traverse; the improvement comprising: spindle assembly mounting means for directly mounting said spindle assembly upon said spindle rail such that said blade is oriented axially central to said ring assembly throughout said range of vertical traverse; said mounting means comprising: a mounting member fixed to said spindle assembly, bearing a spherical convex surface encircling said assembly and extending outwardly thereof, and a mounting flange extending laterally outward from said surface; a spherical concave surface carried by said spindle rail, of complementary arcuity to said convex surface of said mounting member for adjustable abutment therewith and defining a receiving orifice through said spindle rail for said spindle assembly; and joining means a. for directly joining said mounting member flange to said spindle rail, b. for adjustably tilting said spindle blade and assembly to an orientation wherein said ring assembly throughout the range of said traverse is axially concentric to said rotational axis of said spindle blade, and c. for directly fixing said spindle assembly rigidly to said spindle rail at said orientation.
 2. The improvement as in claim 1, wherein said convex spherical surface of said mounting member has its spherical center on said axis of rotation of said blade.
 3. The improvement as in claim 2, wherein said spherical center of said convex surface is on said axis of rotation in the range of the lower half of said blade.
 4. The improvement as in claim 3, wherein said spherical center on said axis of rotation is at an elevation corresponding to the elevation of the lowest wrap of yarn to be wound by said spindle assembly.
 5. The improvement as in claim 1, wherein said concave spherical surface carried by said spindle rail has its spherical center on said axis of rotation of said blade.
 6. The improvement as in claim 1, wherein said joining means is carried in part by said flange and in part by said spindle rail.
 7. The improvement as in claim 6, wherein said joining means includes a portion of said spindle rail circumferential said concave spherical surface carried thereby, formed with a plurality in excess of two holes therethrough, said holes forming a set thereof and being spaced from one another about said concave surface, a portion of said flange of said mounting member circumferential said convex spherical surface thereof, formed with a similar plurality of other holes therethrough forming another set of holes and being similarly spaced from one another about said convex surface as are said holes through said spindle rail, and a simiLar plurality of adjustable joining and fixing members engageable with corresponding parts of said portions of said spindle rail and said mounting member flange through the corresponding holes of said sets thereof.
 8. The improvement as in claim 7, wherein the walls defining the holes of one of said sets have a greater diameter cross section than that of the second set, and the walls of said second set are threaded.
 9. The improvement as in claim 8, wherein said adjustable joining and fixing members are threaded bolts, the bolt heads of which are engageable with one of said portions of said spindle rail and flange and the threaded portions of which are engageable with the threaded walls of said second set of holes, wherein said portion so engageable and said threaded walls are in different ones of said portions of said spindle rail and said flange.
 10. The improvement as in claim 9, wherein said threaded walls are in said spindle rail portion and said concave and convex surfaces in abutment with one another are above the lower horizontal surface of said spindle rail portion.
 11. The improvement as in claim 1, wherein said convex surface is integral with said spindle rail. 